Some say that Portsmouth was founded in AD 501 by a pirate named Port. In fact, there was no significant settlement here until Anglo-Norman lord Jean de Gisors rocked up in the 12th century and created a base from which to trade with France. But: founded by a pirate? That’s a better, and more fitting, story.

That’s because Portsmouth is vitally, thrillingly and heroically bound to the water: it is the UK’s only island city; it’s the home of the oldest operational dry dock in the world; and it’s been the base of the Royal Navy since the service was established by Henry VIII in 1527. It was from Portsmouth that, in 1787, a fleet of 11 ships set off to found the first European colony in Australia. In 1805 Admiral Lord Nelson left from here, bound for the Battle of Trafalgar. On 6 June 1944 – D-Day – Portsmouth was a key embarkation point for vessels destined for Normandy’s beaches. The city is a historical leviathan – and continues to be so today.

Portsmouth has undoubtedly changed: the grime and grunge that once blighted this garrison town have been washed away. Now, it’s shipshape. New developments have seen the city revived – most strikingly in the form of the 170m-high sail-like Spinnaker Tower, which now dominates the waterfront, and offers incredible views over land and sea. In addition, the evidence of all those centuries of maritime mastery is now freshly spruced, gloriously displayed and wonderfully interactive. Wannabe first-mates can dash about the decks of warships, dress-up like Tudor sailors, hear cannons blast, run round castle ramparts and test their mettle on simulated high-seas adventures – all while learning a thing or two. There’s plenty to fill several days, year round, in all weathers, whether your interests lie in medieval dockyards, Tudor wrecks, coastal castles, secret tunnels, commando training or simply the lively restaurants of Gunwharf Quays. In Portsmouth, history isn’t stored fustily behind glass: it is made real; it is there to be delved into, walked amid, touched, smelled and lived.

School of dock

The Historic Dockyard is the heart of Portsmouth. It’s the reason why the city exists, and why it’s been coveted for centuries. And the collection of naval wonders located here has never looked better – or been more fun to explore.

In 2013, the new Mary Rose Museum opened. You can now get closer than ever to the sunk-and-raised Tudor ship – the only 16thcentury warship on display in the world – as well as viewing the 19,000 original artefacts found with her, from longbows and bowls to nit combs that still contain 500-year-old lice! Also new for the Dockyard is the National Museum of the Royal Navy’s Hear My Story exhibition, which brings maritime history to life by revealing personal tales from those who’ve helped make the Navy great over the past century.

Think your family might be up to the task? At Action Stations, housed in old Boathouse 6, pit your wits and daring against the might of the sea in a series of simulators and experiments: try commanding a warship, flying a helicopter, mastering the tides and battling the Royal Marines.

Nelson’s flagship, the HMS Victory, also sits resplendent at the docks. Visit the Great Cabin where the Battle of Trafalgar was planned, the spot where Nelson died, and the cannon-dotted decks where over 800 men worked and fought. You can also see how Victorian sailors lived by hopping aboard the HMS Warrior 1860, the world’s first iron-hulled, armoured warship that was powered by steam as well as sail.

This year sees the 70th anniversary of the D-Day landings, and Portsmouth is home to the D-Day Museum, the UK’s only venue dedicated to this pivotal event – the turning point in the Second World War. It’s a fascinating insight for historians of all ages: archive footage and music transport you back to the 1940s, while atmospheric recreations – an air raid warden’s home during the Blitz, the map room at Allied HQ – bring the sights, sounds and horrors of the period to life. It certainly beats any history lesson. For a more up-to-date take on combat, the Royal Marines Museum follows the history of these extraordinary soldiers from 1664 to the modern day. You can follow a recruit through their rigorous training and on to deployment as well as marvel at the museum’s medal collection. As 2014 has been designated “Survival” year here, there’s even a chance to try some commando training yourself: prepare for a mission, make a compass then take on the outdoor assault course – if you dare!

It was from the battlements of Southsea Castle – which Henry VIII had just had built, to guard the entrance to Portsmouth Harbour – that the monarch watched his ship, the Mary Rose, sink. Over 550 years on, you can stand in the very same spot. The castle, with its solid keep, mighty walls and under-moat tunnels, has stood the test of time, and provides incredible insight into Tudor life – families can don period costumes, negotiate the subterranean passages and learn how the castle would have been defended against invaders. Nearby, at Victorian-era Fort Nelson, you’ll find the Big Guns, 350 weapons that trace the development of artillery from pre-gunpowder machines to hi-tech super guns. Best of all, both are free to visit.

Elsewhere, The Spinnaker Tower, opened in 2005, offers panoramic views of all of historic Portsmouth – the docks, the harbour, the bustling centre – and to the Isle of Wight beyond. It’s the perfect place to end your trip to the city, to survey all the excitement of your stay. Southsea Castle (023-9282 6722; Southseacastle.co.uk; free; open Tue-Sun & bank holiday Mondays, Apr-Oct) Fort Nelson, Fareham (01329 233734; royalarmouries.org; free; open daily) Spinnaker Tower (023-9285 7520; spinnakertower.co.uk; £8.95, child £6.95; open daily)

Travel Essentials

Getting there

Portsmouth is well connected by rail. There are direct routes from London (90 minutes), as well as Bristol, Southampton, Cardiff, Exeter, Reading and Brighton. National Express coaches also serve the city. Road links are good: the A3(M) means London is just 90 minutes away, while the M27/A27 connects Portsmouth with the motorway network.